The high pressure fuel lines deliver the diesel fuel under pressure of approximately 8000 psi (59,000 kPa) from the injection pump to the fuel injectors. The lines expand and contract with the high pressure fuel pulses generated during the injection process. All the high pressure fuel lines are of the same length and inside diameter. Correct line usage and installation is critical.
The high pressure fuel lines must be retained securely in their holders. The lines must not be allowed to contact each other or other components along side of them. If a line fails, it must be replaced with the correct replacement. Repair is not possible.